The subject matter disclosed herein relates to ultrasound probes that may be utilized for diagnostic and/or therapeutic purposes. More particularly, present embodiments are directed to systems and methods that facilitate adjustment of a focus depth of an ultrasound probe between multiple positions while maintaining acoustic coupling.
The term ultrasound generally refers to cyclic sound pressure that has a frequency in a range that is higher than the upper limit of human hearing. A typical ultrasound frequency may include 1 to 20 megahertz. Ultrasound is frequently used for imaging purposes. For example, ultrasound is used in ultrasonography, which is a medical imaging technique that emits high frequency sound waves into a patient's body and detects echoes of the sound waves to produce images of features internal to the patient's body (e.g., blood flow images and intrauterine images). However, ultrasound may also be utilized to perform functions. For example, ultrasound may be utilized to facilitate removal of a buildup of foreign matter from a surface or for therapeutic purposes (e.g., stimulating a damaged muscle).
While there are numerous uses for ultrasound, a representative example may include a medical imaging application. In a typical ultrasound imaging application, sound waves are emitted into a patient's body from a probe and are reflected back to the probe when they hit boundaries. For example, some waves may reflect back to the probe upon reaching a boundary between fluid and tissue and other waves may reflect back to the probe upon reaching a boundary between tissue and bone. The probe detects the reflected waves and relays them to a monitor that utilizes the speed of the ultrasound and the time required to detect the reflected wave relative to the time of emission to calculate the distance from the probe to the reflecting surface. The distances and intensities of the detected waves may then be displayed to provide an image of the observed tissue. Relatively dense tissue may be distinguished from less dense tissue based on a difference in intensity because more dense tissue may reflect more ultrasound waves than less dense tissue.
Many ultrasound probes include an elevational lens that focuses ultrasound energy at a specific and fixed distance from a transducer. However, typical ultrasound images show a range of depths, and it is now recognized that since the depth at which the transducer is focused may not be consistent with a desired image, it may be desirable to adjust the depth at which the transducer is focused.